Birth rate 10/1000 = +population
Death rate 9/1000 = -population
Immigration rate 3/1000 = +population
Emigration rate 7/1000 = -population
10/1000 - 9/1000 + 3/1000 - 7/1000= -3/1000
Growth rate = (-3/1000)(100%)= -0.3%
2 should be placed in the blank to make the equation balance. Btw, that's chemistry and not physics. Get it right.
Because almost all of the force is done by the weight of the person and the mechanism of the swing itself, when you push someone you only give them an increase in velocity, the acceleration comes from the weight at first and then from gravity when the person is coming down, which is why we bend our legs when coming down
